Port of Leith Distillery Oloroso Sherry from Bodegas Barón

A catch 22 in establishing a new Scotch whisky distillery is the requirement for the new make spirit to be matured for a minimum of 3 years in cask before release, while fending off a bank manager keen for his loan to be repaid. Rather than simply riding the the ubiquitous gin band wagon, the new Port of Leith Distillery being constructed in Edinburgh, have struck upon the idea of bottling and marketing the same Oloroso sherry to be used for seasoning their casks, sourced from Bodegas Barón in Sanlúcar.

Not the Usual Suspects

There’s a widely held, but misinformed, conception amongst whisky fans, that the sherry casks used to mature whisky are the one in which the sherry has been matured. Think again. Sherry matures in a solera system, a continuous system of fractional blending made up of numerous tiers of barrels known as criaderas, or nurseries, each containing wine of progressively older age. The butts in each criadera are never emptied, with at most one third taken from every butt each time the saca and rocío, extracting a fraction of the oldest wine and replenishing the barrels take place. The oldest criadera, itself called the solera, holds wine ready to be bottled, replenished with wine from the first criadera. This in turn is replenished with wine from the second criadera, and so on. The last criadera holding the youngest wine, is replenished with wine from the new harvest, called sobretablas.

Solera System

There are two fundamentally different categories of sherry. Biologically aged sherries are fortified to no more than 15-15.5%, allowing them to develop a layer of flor, several strains of indigenous yeast that form on the surface of the wine, protecting the wine from oxidising. The pores in older wooden barrels harbour these indigenous yeasts, which won’t initially be present in new oak barrels, while the new oak tannins also inhibit flor growth prior to being neutralised. Oxidatively aged sherries are fortified to 17% or more, preventing the growth of flor and exposing the wine to oxygen. While oxidation is generally considered a wine fault, when allowed to mature for years the wine becomes rich and complex.

Solera Butts at Bodegas Barón

All these factors mean that solera barrels are not replaced until they are beyond repair, making them almost impossible for the whisky industry to acquire. Why mature whisky in sherry casks anyway? Traditionally sherry was sold straight from the barrels in which it had been shipped, in bars and shops whose patrons would bring their own containers to be filled. These transport casks were not the same as the solera butts, instead were much newer casks made of cheaper European oak, that would often have been used several times for fermenting young wines. The solera butts on the other hand were made of American oak, which is easier to work with and less prone to leaks, reducing the need for maintenance. The fermentation process is significant as it neutralised the casks by extracting the tannins and aromatic compounds from the young oak into the wine, readying them to be filled with mature sherry. Next they were shipped overseas and sold, taking weeks or months, ensuring that the casks became soaked in mature sherry, with easily up to a dozen litres absorbed into the wood’s pores.

Once emptied, shipping the barrels back to Spain was uneconomic, so a symbiotic relationship was born with the Scotch whisky industry, who bought these casks to use for the maturation of whisky. The 1900s saw a shift towards sherry being bottled, though mostly it was still shipped in casks to London for bottling. Exporting bulk sherry in oak barrels continued until the 1970s, with the arrival of stainless steel containers, before being outlawed all together in 1986, when Spanish law stated that the country’s wines must be bottled in Spain. No longer were the transportation casks available to the whisky industry, so alternatives had to be found. William Phaup Lowrie, a Glasgow whisky blender who also dealt in sherry, began seasoning new casks in order to reproduce the profile of a traditional transportation cask.

Typically whisky distilleries have an agreement with a Spanish tonelería, a cooperage who prepare new oak casks made from American white oak (Quercus Alba) or European oak (Quercus Petraea or Quercus Robur), to the distillery’s specified toast level. Quercus Robur would originally have been sourced from Spain, mostly from Galicia in the North, however harvesting is now highly restricted, and most European oak is now sourced from Romania and France. Only Edrington group distilleries, including Macallan and Highland Park, currently have a supply chain for Spanish oak, through the Tevasa cooperage.

Whyte & Mackay Casks at González Byass

These new oak casks will be taken to a sherry bodega for envinado, filling with wine of the type and age specified by the distillery, which remains there for between six months and two and a half years, with eighteen months an industry standard. Whilst in the cask, the wine modifies the flavour compounds of the oak, stripping harsh tannins, bitter and sulphury notes from the freshly toasted oak, which would otherwise negatively impact maturating whisky. In addition to the dozen or so litres of wine that will be absorbed by the pores of the oak, a few litres will be left in the cask to prevent it drying out to the journey to Scotland. This would usually be emptied out before filling with whisky, though a little may remain, especially in the wet or fresh sherry cask expressions that have been produced by a few distilleries. With seasoning done, the wine will be emptied out, then often reused several times before being discarded, after which it will typically be distilled into sherry brandy or made into sherry vinegar. Uncoincidentally, one of the largest producers of sherry casks for the whisky industry, Páez Lobato, are also the largest producer of sherry vinegar, Páez Morilla.

Fernando de Castilla Cask Bruichladdich

Seasoning sherry casks for the Scottish whisky industry is now an established business in which many bodegas have an operation, often in partnership with a cooperage. Visiting Fernando de Castilla in 2017 we were told by the bodega’s Fernando Romero that their barrels are sold only to the Islay distillery Bruichladdich. At González Byass we were able to take a look into one of the bodega’s warehouses where barrels were being seasoned for Whyte & Mackay, though our host Simon Leth-Nissen appeared slightly wary about too many pictures being taken.

While the transport casks of old were filled with sherry intended for drinking, seasoning modern casks with such long aged and high quality sherry typically just isn’t economically viable. Whilst exceptions exist, most are filled with lower quality wines often destined for vinegar. Why couldn’t drinking quality sherries go on to be bottled and sold as such after being used for seasoning casks for the whisky industry? Because just as the sherry seasons the oak barrels, the same new oak would affect the sherry – remember that sherries are matured in a solera system built of rarely replaced, very old oak barrels that will have little influence. A paradox here is the trend for distilleries to state the bodega that seasoned the casks for their whisky, which is arguably misleading where it’s not that bodega’s drinking sherry being used to season the casks. Discuss.

Oloroso Butt at Bodegas Barón

An exception to this rule is the new Port of Leith Distillery being constructed in Edinburgh, who will mature the spirit they produce in casks seasoned with Oloroso from a 50 year old solera at Bodegas Barón in Sanlúcar de Barrameda, originally established in 1631. A catch 22 in establishing a new Scotch whisky distillery is the requirement for the new make spirit to be matured for a minimum of 3 years in cask before release, while fending off a bank manager keen for his loan to be repaid. Numerous new distilleries have tackled this issue by marketing unaged spirits, usually the ubiquitous gin. More innovatively, the Port of Leith Distillery, rather than jumping aboard this band wagon, have struck upon the idea of having bottling and marketing the same sherry to be used for seasoning their casks.

Bodegas Barón Old & New

Bodegas Barón was established by Manuel Barón Fernández in 1895, when he acquired some old soleras from almacenista Anselmo Paz, along with his wife Dolores Romero Sanchez, whose family had history in sherry dating back to the 17th century. Many generations later in 1984, the bodega was acquired by businessman Jose Rodriguez Jimenez, whose sons Juan Luis Rodriguez Carrasco and Jose Rodriguez Carrasco have now taken over the reins. Barón’s original bodega Molinillos is located at the lower end of the Barrio Alto district of Sanlúcar, facing the river whose sea breezes help cool and maintain humidity of the bodega. The central warehouses date back to the bodega’s foundation in 1631, where Anselmo Paz’s original soleras are still maintained, containing traces of the 150 year old plus wines. There’s a newer bodega in the outskirts of town, bringing their total number of butts to around ten thousand. Barón own several albariza vineyards in the pagos surrounding Sanlúcar, most notably the prized vineyard Finca El Poedo, sited within the Jerez Superior area and sloping towards the Guadalquivir estuary, helping to maintain good moisture in the soils.

Port of Leith Distillery Oloroso Sherry from Bodegas Baron

Port of Leith Distillery Oloroso Sherry from Bodegas Barón

Classic oloroso character of dried fruits, prune, sultana and fig, balanced with tropical fresh and dried banana, mango, and generous gingery spice and black pepper, followed by herbal bouquet garni notes. Resinous charred oak and toast, coffee, nutty hazelnut and walnut, classic oloroso whilst retaining a fresh and vibrant saline spine suggestive of fresh apple juice. Textured glycerol richness on the palate, nicely balanced by the concentration of spice and fruit character, along with noticeable alcohol and a touch of acidity. Very tasty, though the palate lacks a touch of complexity, and the finish could be a little longer, overall great value.